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A macrophage migration inhibition test showed that the blood lymphocytes of 15 of 27 sheep inoculated in utero or at birth with disrupted cells from ovine malignant lymphomas responded in culture to antigens derived from three other lymphomas. A close association was seen between animals whose lymphocytes were antigen-sensitive and those which developed lymphocytosis. This association and the specificity of reaction between the various tumour antigens employed in the tests is interpreted as further evidence toward a viral aetiology in ovine malignant lymphoma.  相似文献   

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Miniature (20 g) Cheddar-type cheeses were manufactured using enzymes extracted from the crustacean Munida or chymosin as coagulant. Cheeses were ripened at 8 degrees C and samples were collected for analysis after 2, 6 and 12 weeks. Proteolysis was assessed by urea-polyacrylamide gel electrophoresis, which showed that cheeses manufactured with the Munida extracts had a higher extent of degradation of beta-casein than cheeses made using chymosin as coagulant. Patterns of proteolysis were also obtained by reverse-phase high-performance liquid chromatography (RP-HPLC) and matrix assisted laser desorption ionisation-time of flight (MALDI-ToF) mass spectrometry. In general, the products of proteolysis were more complex in cheese made using the Munida extracts than in cheese made by chymosin as coagulant. Statistical analysis of results clearly discriminated the cheeses on the basis of coagulant used. Molecular mass of peptides found in cheese made using Munida extracts were similar to those of peptides commonly detected in cheeses made using chymosin as coagulant.  相似文献   

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P. H. Braz‐Silva, M. H. C. G. Magalhães, V. Hofman, K. L. Ortega, M. I. Ilie, G. Odin, P. Vielh and P. Hofman Usefulness of oral cytopathology in the diagnosis of infectious diseases In recent years, the incidence of oral opportunistic infections has increased, partly due to the widespread implementation of organ and bone marrow transplantation and the increase in the prevalence of human immunodeficiency virus (HIV) infection. Cytology can be used as a rapid, inexpensive and simple routine procedure in diagnosing infectious diseases of the mouth. Moreover, ancillary methods can be applied to cytological samples, increasing the specificity and sensitivity for the diagnosis of infectious diseases. This review describes the cytopathological features of the main viral, fungal, bacterial and parasitic infections of the mouth. Cytological techniques of specimen collection, identification of infectious agents by cytomorphological approaches and ancillary methods, and diagnostic pitfalls will be discussed.  相似文献   

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The nonallelicgib-1 andgib-3 tomato (Lycopersion esculentum Mill.) mutants are gibberellin deficient and exhibit a dwarfed growth habit. Previous work has shown that this dwarfed growth pattern can be reversed by the application of a number of gibberellins and their precursors, includingent-kaurene (ent-kaur-16-ene). This indicates that they are blocked in gibberellin biosynthesis at a step prior toent-kaurene metabolism. The normal accumulation of carotenoids observed in these mutants suggests a functionally normal isoprenoid pathway.Ent-kaurene is synthesized from geranylgeranyl pyrophosphate in a two-step process with copalyl pyrophosphate as an intermediate.In vitro assays using young fruit extracts from wild-type andgib-2 plants resulted in the conversion of geranylgeranyl pyrophosphate to copalyl pyrophosphate, and the conversion of copalyl pyrophosphate toentkaurene. Similar assays usinggib-1 plants indicated a reduced ability for synthesis of copalyl pyrophosphate from geranylgeranyl pyrophosphate, and thus a reducedent-kaurene synthetase A activity. Furthermore,gib-3 extracts demonstrated a reduced ability to synthesizeent-kaurene from copalyl pyrophosphate, and thus a reducedent-kaurene synthetase B activity. These results establish the enzymatic conversion of geranylgeranyl pyrophosphate to copalyl pyrophosphate, and copalyl pyrophosphate toent-kaurene, as the sites of the mutations ingib-1 andgib-3 tomatoes, respectively. We also note that tomato fruit extracts contain components which are inhibitory toent-kaurene synthesis.  相似文献   

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The usefulness of galactomannan detection using the Platelia Aspergillus test for the diagnosis of invasive aspergillosis was studied in 849 sera from 54 hematological patients with prolonged neutropenia, which were classified according to the risk for invasive aspergillosis. Three patients developed a proven invasive aspergillosis, one a probable invasive aspergillosis and 17 patients a possible invasive aspergillosis. Thirty-three patients showed no evidence of invasive aspergillosis. All patients with proven invasive aspergillosis had a high risk for invasive aspergillosis, while the one having probable invasive aspergillosis had intermediate risk. Detection of galactomannan in this study showed a sensitivity of 66.7% for patients with proven invasive aspergillosis and 50% for patients with proven and probable invasive aspergillosis. The specificity was 98% or higher in all groups studied. The predictive positive and negative values for patients with proven invasive aspergillosis were 66.7% and 98%, respectively. A rise in the concentration of galactomannan was observed in patients who failed to respond to the antifungal treatment. Galactomannan antigenemia preceded post-mortem histological diagnosis of invasive aspergillosis in two patients by 17 and 81 days, respectively. In conclusion, detection of galactomannan by the Platelia Aspergillus test allows for a specific and relatively sensitive diagnosis of invasive aspergillosis in hematological patients with a high and intermediate risk for invasive aspergillosis.  相似文献   

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Studies on modification of diagnostic test for pertussis have been continued, they were practically restricted to an application of passive haemagglutination micromethod. Six hundred and twenty eight sera from children suspected to be infected with Bordetella and 38 sera of control children suffering from non-infectious diseases were tested. Despite of the fact that higher titers were obtained with method using red blood cells preserved in Alsevier solution, the passive haemagglutination micromethod may be used in field studies especially during pertussis epidemics what was confirmed by statistical analysis.  相似文献   

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目的比较甲真菌病病原体检测中多点平皿培养法与常规试管培养法的差异。方法选择2004年10月~12月及2005年10月~12月病甲标本,分别采用多点平皿培养法(试验组)和常规试管培养法(对照组)分离病原体并作菌种鉴定。结果多点平皿培养法和常规试管培养法之间比较,阳性率分别为68.4%和49.3%(P=0.0029),污染率分别为13.2%和4.6%(P=0.0246)。致病菌分离结果:对照组皮肤癣菌75.7%,酵母菌18.9%,非皮肤癣菌霉菌5.4%;试验组则分别为46.2%,34.6%和16.7%。两组分离菌种比较,P值均<0.05。试验组共检出2例混合感染,对照组则无。结论多点平皿培养法阳性率高,可以提高对甲真菌病的病原菌的检出率,尤其是对非皮肤癣菌酵母菌和霉菌的检出率,且有助于发现甲真菌病的混合感染。但多点平皿培养法污染率亦高,应规范无菌操作。  相似文献   

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Extracts of leaves of Ginkgo biloba (family Ginkgoaceae), widely used in the treatment of peripheral and cerebral circulatory disorders as well as for dementia of different aetiology, contain long chain alkylphenols (with allergenic, cytotoxic, mutagenic and tumour-promoting properties) together with the extremely potent allergens, the urushiols. Such hazardous compounds can be present only in very low concentrations in phytopharmaceutical preparations and hence, for the purposes of drug safety, techniques must be available for the identification and quantification of these allergens at extremely low levels in refined manufactured materials. GC-MS analysis of samples collected at various stages during the production process of a standardised extract of G. biloba (EGb 761) demonstrated that all alkylphenols present in the primary acetone extracts were removed in parallel with the same efficiency irrespective of their aromatic substitution pattern. Furthermore, in the final product the content of urushiols was generally below the detection limit of 0.03 ppm. Therefore, it is concluded that demonstrating the absence of the predominant, and easily quantifiable, ginkgolic acids provides a reliable means for the control of pharmaceutical quality of the final product.  相似文献   

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